Hi PPl
The issue is I had created one domain as Engine.com and a child domain as clutch.engine.com
Due to some reasons I had to format clutch.engine.com and I have removed some entries from DC (Engine.com) however in Active Directory Domains and trust I am unable to remove clutch.engine.com
I refered

I googled for this issue and after trying many solution i came across something which works .
I hope it will help others also so I m sharing the step with u

1. Click Start, click Run, type ntdsutil, and then press ENTER.
2. At the Ntdsutil command prompt, type domain management, and then press ENTER.
3. Type connections, and then press ENTER.
4. Type connect to server Domain_Controller_Name, and then press ENTER.
5. After the following message appears, type quit, and then press ENTER:
Connected to Domain_Controller_Name using credentials of locally logged on user
6. At the domain management prompt, type list, and then press ENTER.
7. Note the following entry:
DC=DomainDnsZones,DC=Child_Domain, DC=extension
For example, if the child domain is Contoso.com, note the following entry:
DC=DomainDnsZones,DC=contoso,DC=com
8. Type the following command, and then press ENTER.
delete nc dc=domaindnszones,dc=Child_Domain,dc=extension
Note In this command, Child_Domain represents the name of the child domain that you want to remove. For example, if the child domain is Contoso.com, type the following command, and then press ENTER:
delete nc dc=domaindnszones,dc=contoso,dc=com
9. Quit Ntdsutil.